Black Holes: Can Anything Reduce Their Size?

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Discussion Overview

The discussion revolves around the possibility of reducing the size of black holes or accelerating their evaporation through processes or materials, including the potential for man-made approaches. Participants explore theoretical frameworks, particularly in relation to Hawking radiation and the implications of general relativity (GR) and quantum mechanics (QM).

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions whether there is any process or material that could reduce the size of a black hole or accelerate its evaporation, suggesting that this might be an unrealistic idea.
  • Another participant acknowledges the existence of Hawking radiation as a natural process for black hole evaporation but emphasizes its slow nature.
  • Some participants express skepticism about the feasibility of man-made methods to stimulate black hole evaporation, noting that current understanding is governed by GR and that QM effects like Hawking radiation are anomalies.
  • A participant raises the question of whether there would be any practical benefits to speeding up black hole evaporation, particularly in the context of potential collisions with Earth.
  • There is a clarification about the gravitational effects of black holes, indicating that they are not inherently more dangerous than stars of the same mass unless one approaches the event horizon.

Areas of Agreement / Disagreement

Participants generally agree that current theoretical frameworks do not support the idea of reducing black hole size or accelerating evaporation through man-made means. However, there is no consensus on the implications of black hole behavior or the potential benefits of such processes.

Contextual Notes

The discussion highlights the limitations of current theoretical understanding, particularly the unresolved nature of quantum gravity and its potential impact on black hole behavior.

elusiveshame
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I'm pretty sure I know the responses I'm going to get, as this question is pretty silly, but I'll ask anyway.

Is there anything - a process, or a material, that would reduce the size of a black hole and/or evaporate it away quickly, or is that just hocus pocus thinking?
 
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elusiveshame said:
Is there any other way that could happen by a man-made approach that would accelerate the evaporation?
I don't think that's a silly question at all! I suspect that the answer is no. But, the idea of some sort of stimulated evaporation is a lot more plausible than some of the really silly questions we get.

That said, currently black holes are governed theoretically by GR, with the QM effect of Hawking radiation being something of an anomaly. If and when we have a theory of quantum gravity, then the possibilities for how a black hole behaves may change.
 
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PeroK said:
I don't think that's a silly question at all! I suspect that the answer is no. But, the idea of some sort of stimulated evaporation is a lot more plausible than some of the really silly questions we get.

That said, currently black holes are governed theoretically by GR, with the QM effect of Hawking radiation being something of an anomaly. If and when we have a theory of quantum gravity, then the possibilities for how a black hole behaves may change.

Thanks for the answer. That's what I figured the likely answer would be: no

Would there be any benefit to speeding up that process (if it were possible and plausible to do so) aside from maybe preventing a head on collision with one, if one were detected to be heading towards us? When a BH evaporates, there's no point in which we'd be able to "see inside" of it because it'd still be shrouded by the event horizon, yeah? Or would it become "visible" once the mass reaches a certain level?
 
elusiveshame said:
Would there be any benefit to speeding up that process (if it were possible and plausible to do so) aside from maybe preventing a head on collision with one, if one were detected to be heading towards us? When a BH evaporates, there's no point in which we'd be able to "see inside" of it because it'd still be shrouded by the event horizon, yeah? Or would it become "visible" once the mass reaches a certain level?
A black hole is not a mass-eating monster! The gravity of the black hole is the same as the collapsed star from which it formed - as long as you remain beyond the original surface radius of the star. I.e. if the Sun became a black hole, this would not directly affect the Earth's orbit. It's only if you get within the original suface radius that the gravity is greater - and once you reach the event horizon, then there is no going back.

In that sense, a black hole would be no more dangerous than a rogue star of the same mass. And, the danger of a rogue star is extremely low risk.
 
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PeroK said:
A black hole is not a mass-eating monster! The gravity of the black hole is the same as the collapsed star from which it formed - as long as you remain beyond the original surface radius of the star. I.e. if the Sun became a black hole, this would not directly affect the Earth's orbit. It's only if you get within the original suface radius that the gravity is greater - and once you reach the event horizon, then there is no going back.

In that sense, a black hole would be no more dangerous than a rogue star of the same mass. And, the danger of a rogue star is extremely low risk.
D'oh. I feel like I knew this, too. Thanks for the reminder :)
 

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